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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Sun Aug 21, 2011 6:32 pm Post subject: Puzzle 11/08/21: ~ XY |
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Code: | +-----------------------+
| . . 4 | 5 . 6 | . 9 8 |
| . . 2 | 4 . . | . . 7 |
| 6 7 5 | . . . | . . 4 |
|-------+-------+-------|
| 9 5 . | 6 8 . | . . 3 |
| . . . | 7 3 . | . . . |
| 7 . . | . . 9 | . . . |
|-------+-------+-------|
| . . . | . . . | 9 . 2 |
| 3 . . | . . . | . 4 . |
| 5 2 9 | 3 . . | 8 . . |
+-----------------------+
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Play this puzzle online at the Daily Sudoku site |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Mon Aug 22, 2011 4:40 am Post subject: |
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XY-Chain. 6 in r9c5 proves 4 in r4c6; r6c5<>4
Skyscraper; r6c9, r8c7<>1
W-Wing (56), SL 5 in r8; r56c7<>6 |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Mon Aug 22, 2011 1:50 pm Post subject: |
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I finally found some time for Sudoku.
Two solutions; a one stepper and a two stepper.
aur(29)r38c45 external sis: r3c6=2, r8c6=2; r4c6<>2
or
axy-wing(24-1)[r49c6+r6c4]=(7)r9c6-r9c8=r8c7-(7=4)r4c7-(4=2)r4c6-(2=1)r6c4; r5c6,r78c4<>1
Type 1 UR(29)r38c45; r8c5<>29=6
Ted |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Mon Aug 22, 2011 5:45 pm Post subject: |
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Aaaagh!!! I really need to add external SIS logic to my UR() routine.
Nice find, Ted. |
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ronk
Joined: 07 May 2006 Posts: 398
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Posted: Mon Aug 22, 2011 9:32 pm Post subject: |
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daj95376 wrote: | I really need to add external SIS logic to my UR() routine.
Nice find, Ted. |
tlanglet, I second the nice find.
daj95376, Ted's AUR would be destroyed by a co-existent "UR+3C/2SL" for r8c4<>2.
here Mike Barker wrote: | Code: | --- UR+3C/2SL: both strong links share a node, do not include the bivalue cell and have equal labels => "b" can be removed from "abZ"
ab abX
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a|
a |
abY-----abZ |
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How would you avoid that in your solver? |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Tue Aug 23, 2011 3:37 am Post subject: |
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ronk wrote: | daj95376, Ted's AUR would be destroyed by a co-existent "UR+3C/2SL" for r8c4<>2.
Code: | Mike Barker--- UR+3C/2SL: both strong links share a node, do not include the bivalue cell and have equal labels => "b" can be removed from "abZ"
ab abX
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a|
a |
abY-----abZ
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How would you avoid that in your solver?
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That UR elimination is one of two found by my solver.
Code: | +--------------------------------------------------------------+
| 1 3 4 | 5 7 6 | 2 9 8 |
| 8 9 2 | 4 1 3 | 56 56 7 |
| 6 7 5 | 289 29 28 | 3 1 4 |
|--------------------+--------------------+--------------------|
| 9 5 1 | 6 8 24 | 47 27 3 |
| 2 468 68 | 7 3 145 | 1456 568 9 |
| 7 468 3 | 12 245 9 | 1456 2568 156 |
|--------------------+--------------------+--------------------|
| 4 168 678 | 18 56 1578 | 9 3 2 |
| 3 168 678 | 1289 269 1278 | 1567 4 156 |
| 5 2 9 | 3 46 147 | 8 67 16 |
+--------------------------------------------------------------+
# 63 eliminations remain
r38c45 <29> UR via s-link <> 2 r8c4
r25c78 <56> UR via s-link + N_Singles <> 6 r5c7
<s list-only>
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Code: | after r8c4<>2 from strong links UR logic
+--------------------------------------------------------------+
| 1 3 4 | 5 7 6 | 2 9 8 |
| 8 9 2 | 4 1 3 | 56 56 7 |
| 6 7 5 | 289 29 28 | 3 1 4 |
|--------------------+--------------------+--------------------|
| 9 5 1 | 6 8 24 | 47 27 3 |
| 2 468 68 | 7 3 145 | 1456 568 9 |
| 7 468 3 | 12 245 9 | 1456 2568 156 |
|--------------------+--------------------+--------------------|
| 4 168 678 | 18 56 1578 | 9 3 2 |
| 3 168 678 | 189 269 1278 | 1567 4 156 |
| 5 2 9 | 3 46 147 | 8 67 16 |
+--------------------------------------------------------------+
# 62 eliminations remain
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However, that wouldn't prohibit my solver from continuing with the potential <29> UR.
Awhile back, I re-wrote all of my UR routines to rely on finding an X-pattern in two digits (under UR conditions). The potential UR condition would still be detected because this pattern of candidates still remain.
Code: | X-pattern in {2,9}
+-----------------------------------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | 2 9 . | . . . |
|-----------+-----------+-----------|
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
|-----------+-----------+-----------|
| . . . | 9 2 . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+-----------------------------------+
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In fact, thats how my solver detects a UR Type 1.1 elimination where three of the cells are solved and an elimination exists in the fourth cell.
Code: | UR Type 1.1 => r3c5<>b
+-----------------------------------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | a bX . | . . . |
|-----------+-----------+-----------|
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
|-----------+-----------+-----------|
| . . . | b a . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+-----------------------------------+
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Regards, Danny |
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Ertekaz
Joined: 28 Aug 2013 Posts: 1
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Posted: Wed Aug 28, 2013 3:59 am Post subject: |
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Never understand Yet |
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